M-7.0, 5.7 quakes hit Alaska
Back-to-back earthquakes measuring 7.0 and 5.7 shattered highways and rocked buildings Friday in Anchorage, sending people running into the streets and briefly triggering a warning to residents in Kodiak to flee to higher ground for fear of a tsunami.
The warning was lifted without incident a short time later. There were no immediate reports of any deaths or serious injuries.
The U.S. Geological Survey said the first and more powerful quake was centered about 12 kilometers north of Anchorage, Alaska’s largest city, with a population of about 300,000. People ran from their offices or took cover under desks.
A large section of an off-ramp near the Anchorage airport collapsed, marooning a car on a narrow island of pavement surrounded by deep chasms in the concrete. Several cars crashed at a major intersection in Wasilla, north of Anchorage, during the shaking.
LDOCEには “a very deep space between two areas of rock or ice, especially one that is dangerous” や “a big difference between two people, groups, or things” と定義されています。危険を伴う大きな割れ目のことを表すようです。
同じく割れ目を表す語crackがあり、違いが気になったので調べてみました。そちらは “a very narrow space between two things or two parts of something” や “a thin line on the surface of something when it is broken but has not actually come apart” とあるように、小さなすき間や、分離せずにひびが入った状態のことをさすことがわかりました。（aqua）